Imp Questions For All Chapters – Geography Class 7
Air Pressure
Short Questions
1. What is air pressure?
Answer: Air pressure is the force exerted by air on the surface of the Earth.
2. What happens to air pressure as altitude increases?
Answer: Air pressure decreases as altitude increases.
3. Which instrument is used to measure air pressure?
Answer: A barometer is used to measure air pressure.
4. Why is air pressure maximum at sea level?
Answer: Due to Earth’s gravity, air is denser and exerts more pressure at sea level.
5. What effect does temperature have on air pressure?
Answer: Higher temperature causes lower air pressure as air expands and rises.
6. Which pressure belt is found between 5° North and 5° South?
Answer: The Equatorial Low-Pressure Belt.
7. Why are deserts found near 30° latitude?
Answer: High-pressure belts in this region create dry conditions, leading to deserts.
8. What are isobars?
Answer: Isobars are lines on a map that join places of equal air pressure.
9. What is the main cause of wind movement?
Answer: Differences in air pressure cause wind to move from high to low pressure areas.
10. Which factor influences air pressure the most?
Answer: Temperature, altitude, and water vapor content influence air pressure.
Long Questions
1. How does altitude affect air pressure?
Answer: As altitude increases, the density of air decreases because there are fewer air molecules at higher levels. This results in lower air pressure in mountainous or high-altitude regions.
2. Why does hot air rise and create low pressure?
Answer: When air is heated, it expands, becomes lighter, and rises, creating a low-pressure area. This is why equatorial regions with high temperatures usually have low-pressure belts.
3. Why are high-pressure belts located near 30° latitude?
Answer: The heated air from the equatorial region rises, moves towards higher altitudes, cools down, and sinks at 30° latitude. This creates a high-pressure belt, leading to dry conditions.
4. What is the relationship between temperature and pressure belts?
Answer: High temperatures at the equator create low-pressure belts, while cooler temperatures at the poles create high-pressure belts. This uneven heating influences global wind patterns.
5. How does air pressure influence weather phenomena?
Answer: Changes in air pressure cause storms, winds, and precipitation. Low-pressure areas bring rain and storms, while high-pressure areas often result in clear skies.
6. Why is the sub-polar low-pressure belt formed?
Answer: The sub-polar region experiences strong winds that reduce friction with the Earth’s surface. The Earth’s rotation also pushes air outward, leading to a low-pressure belt at 55°–65° latitude.
7. What happens to the pressure belts during different seasons?
Answer: Due to the tilt of the Earth, pressure belts shift 5°–7° north during summer (Uttarayan) and south during winter (Dakshinayan), affecting global weather patterns.
8. How does the equatorial low-pressure belt influence rainfall?
Answer: Warm air rises in the equatorial region, causing condensation and heavy rainfall. This leads to the formation of tropical rainforests in equatorial regions.
9. Why are polar regions characterized by high pressure?
Answer: The polar regions remain cold throughout the year, making the air dense and heavy. This cold, sinking air creates high-pressure belts between 80°–90° latitude.
10. What is the role of air pressure in wind formation?
Answer: Wind is formed due to differences in air pressure. Air moves from high-pressure areas to low-pressure areas, creating wind patterns like trade winds and westerlies.
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